When people discovered that they could generate power with a water wheel, they also discovered the secret to how batteries store and transfer electric energy.

You might think that when you add a battery to an electronic machine, the electricity is simply stored and then later, when it’s needed, unleashed, which is almost right. More accurately, negatively charged electrons are drawn to travel to the positive side of a battery, and they’re willing to transfer energy (in the form of powering up your device) in the process.

You can use a battery, fuel cell, or solar cell to store and deliver energy and they will all work the same way.

A motor works in the opposite direction as a generator (which converts mechanical energy into electrical energy), converting electrical energy into mechanical energy with the help of an electromagnet. Electromagnets are pretty awesome; they can be strong enough to lift 2000 lb. cars.

Batteries, fuel cells, and solar cells all produce direct current (DC). Current always flows in the same direction between the positive and negative terminals of a battery.

Power from a power plant, on the other hand, is alternating current (AC). In the US, the direction of the current reverse (or alternates) 60 times per second and 50 times per second in Europe.

Modern batteries use a variety of chemicals to power their reactions. Common battery chemistries include:

Zinc-carbon battery: The zinc-carbon chemistry is common in many inexpensive AAA, AA, C and D dry cell batteries. The anode is zinc, the cathode is manganese dioxide, and the electrolyte is ammonium chloride or zinc chloride.

Alkaline battery: This chemistry is also common in AA, C and D dry cell batteries. The cathode is composed of a manganese dioxide mixture, while the anode is a zinc powder. It gets its name from the potassium hydroxide electrolyte, which is an alkaline substance.

Lithium-ion battery (rechargeable): Lithium chemistry is often used in high-performance devices, such as cell phones, digital cameras and even electric cars. A variety of substances are used in lithium batteries, but a common combination is a lithium cobalt oxide cathode and a carbon anode.

Lead-acid battery (rechargeable): This is the chemistry used in a typical car battery. The electrodes are usually made of lead dioxide and metallic lead, while the electrolyte is a sulfuric acid solution.

Want to know more about electricity? Give us a call, we’re the experts.